1. Field of the Invention
The present invention relates to a technical field of speakers.
2. Description of the Related Art
A speaker is a so-called electroacoustic transducer for converting an electric signal (electric energy) from an amplifier to an acoustic signal (acoustic energy). In terms of its principle of operation, it is general to vibrate a diaphragm by a voice coil disposed in a magnetic circuit. An electric signal corresponding to a lead reproduced sound to the voice coil.
There are various forms in the shape of the diaphragm. In a dome speaker, the diaphragm has a dome shape. FIG. 6 shows a fragmentary sectional view of a dome speaker in the related art. FIG. 7 shows a bottom view of the dome speaker in the related art. In the dome speaker, a lead wire L led out from a voice coil (not shown) is wired around a surface of an edge damper portion 1 of the diaphragm. Then, the lead wire L is bent to follow an outer periphery of a frame 2 at an end of the edge damper portion 1. The lead wire L is connected to an external terminal 3. The external terminal 3 has a through hole 3a. The lead wire L is led to the bottom surface of the external terminal 3 through the through hole 3a. The lead wire L and the external terminal 3 are soldered at the bottom surface of the external terminal 3.
If a connecting portion 4 is thus exposed at the bottom surface of the external terminal 3, in a case where the speaker is built into electronic equipment or the like, there are cases where the connecting portion 4 comes into contact with another part, and the contacted part and/or speaker is electrically destroyed. Hence, there has been a problem in the perspective of safety.
In addition, since the dome speaker is suitable for making the equipment thin, the dome speaker is often used for compact portable equipment. High-density mounting is required in such applications, but it is necessary to provide a predetermined clearance in the layout so that the connecting portion and the other part do not contact each other.